Vitamin D Supplementation does not reduce Exacerbations of COPD

Abnormal inflammatory response of the airways, characterized by emphysema and chronic bronchitis, after inhalation of noxious gases, particularly cigarette smoke, is called as chronic obstructive pulmonary disease (COPD). There is a progressive decline in the lung functions, including forced expiratory volume (FEV1), and the patient can experience exacerbations when exposed to infections. Impaired FEV1 is often found to be associated with low serum 25- hydroxy- vitamin D. Almost 60% to 75% patients of COPD have been found to have low serum vitamin D levels.

Many physicians have opined that vitamin D deficiency may lead to an increase in airway inflammation, reduced clearance of bacteria, and an increase in exacerbations of COPD. Therefore, they suggest vitamin D supplementation as a way to prevent the exacerbations. However, a recent study published in the journal Annals of Internal Medicine has found that vitamin D supplementation does not reduce exacerbation of COPD.

The study was carried out at University Hospitals Leuven, Belgium. 182 patients suffering from moderate to severe COPD with a recent history of exacerbation were selected for the study and randomly divided into two groups. They were either given 100 000 IU of vitamin D supplementation or placebo, every 4 weeks for one year. The researchers followed up the patients for the rate of exacerbations, duration between vitamin D supplementation and first exacerbation, hospitalizations, lung functions and their overall quality of life.

It was seen that vitamin D supplementation lead to a significant increase in the levels of serum vitamin D. However, it did not lead to any change in the rate of exacerbation of COPD, nor did it affect the lung function. The rate of exacerbations was reduced only in those patients who suffered from a severe vitamin D deficiency at the start of the study. These observations have led the researchers to believe that vitamin D supplementation does not reduce the exacerbations of COPD. However, this was a one off study with less number of participants. Therefore, further studies are needed before one can reach to any definite conclusion.

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